The problems of air pollution, diminishing supply and increasing expense have prompted efforts to develop a feasible alternative fuel to hydrocarbons, i.e., gasoline, for use in all types of engines, particularly piston driven and rotary internal combustion engines, gas turbines, and stirling engines. The search for an alternative fuel to replace gasoline as the primary fuel used in engines has for some time focused on hydrogen. Hydrogen appears to be an ideal solution to the problems inherent in the use of gasoline as a fuel because hydrogen is available in water in an inexpensive and virtually inexhaustible supply, and, when hydrogen burns, the exhaust is pollution-free water vapor.
Prior efforts towards developing hydrogen fueled vehicles have involved both storage of the hydrogen gas on the vehicle and on-board generation of the hydrogen gas. While substantial efforts have been made to develop hydrogen storage systems, such storage systems are not presently practical because of the problems of hydrogen distribution to motorists and the danger posed by the storage of a substantial amount of hydrogen.
Prior efforts to develop an on-board hydrogen generation system have involved manifold hydrogen generators using steam or water on catalyst at high temperatures to generate hydrogen. The hydrogen generator unit is mounted outside the engine in heat transfer relationship with the exhaust manifold to use the heat generated by the engine in the hydrogen generation process. The hydrogen is routed through the engine carburator and then into the combustion engine. Examples of such prior manifold hydrogen generator units are U.S. Pat. Nos. 2,295,209; 3,653,364; 4,037,568; and 4,256,060. A significant limitation on such manifold hydrogen generator units is the fact that the steam or water on catalyst process for generating hydrogen works best at temperatures in the super heated range which are usually not feasible to obtain with the amount of heat generated in exhaust manifolds. Accordingly, these manifold units are either limited by the quantity of hydrogen generated or must include supplemental heating means to provide the heat required to reach the super heated temperatures, thereby adding to the cost and decreasing the efficiency of such units. Manifold hydrogen generator units are mostly used as generators of hydrogen for use as a supplemental fuel with gasoline.
Another major problem with manifold hydrogen generator units is catalyst deactivation whereby the surface of the catalyst becomes oxidized and inoperative to generate hydrogen until it is rendered active, i.e., reactivated, by removal of the oxidation. Prior techniques for reactivating the deactivated catalyst include replacing the catalyst, e.g., U.S. Pat. No. 2,295,209 and 3,653,364; or physically removing the oxidation by brushing or other physician contact or agitation as in U.S. Pat. No. 4,256,060. It is also known, e.g., U.S. Pat. No. 4,547,356, to use hydrogen as a reducing agent to remove the oxygen from the catalyst surface and thereby regenerate or reactivate the catalyst.
In general, prior hydrogen generation units have been used to generate on-board fuel for engines, but there is a need to generate larger quantities of hydrogen more efficiently and to more effectively inject the hydrogen into the combustion chamber of the engine.
Accordingly, it is an object of this invention to provide a new and improved method of and apparatus for generating and injecting hydrogen in an engine.
It is another object of this invention to provide a new and improved method of and apparatus for generating hydrogen from water, or steam, or moist air, or hydrogen and steam, on-board a vehicle.
It is another object of this invention to provide a new and improved method of and apparatus for generating and simultaneously injecting hydrogen fuel directly into the combustion chamber of an engine.
It is another object of the present invention to provide a new and improved method of and apparatus for generating and injecting hydrogen into the combustion chamber of an engine involving a catalytic process in which deactivated catalyst is reactivated by the combustion process in the combustion chamber.
It is another object of the present invention to provide a new and improved method of and apparatus for generating hydrogen on-board a vehicle powered by an engine comprising an injector having a chamber which communicates with the compression chamber and including a catalyst from which hydrogen is generated.